In a wireless communication system that uses Long Term Evolution (LTE), a base station apparatus performs allocation of a radio resource and determination of a Modulation and Coding Scheme (MCS), based on channel quality information of each terminal apparatus. Accordingly, when transmission in downlink is performed, in order to perform the allocation of a suitable radio resource and the determination of the MCS on each terminal apparatus, the base station apparatus acquires, in advance, feedback information relating to a channel from each terminal apparatus.
The feedback information relating to the channel is referred to as Channel State Information (CSI). For example, a Channel Quality Indicator (CQI), a Rank Indicator (RI), a Precoding Matrix Indicator (PMI), a Beam Indicator (BI), a CSI Reference signal resource Indicator (CRI), and the like are included in the CSI. For example, in a case where an error rate is set in advance to 0.1, the terminal apparatus feeds a maximum value of the CQI that does not exceed 0.1 which is an error rate that is set based on a result of channel measurement, as the CQI, back to the base station apparatus.
Furthermore, in the wireless communication system that uses LTE, two types of CQIs, a Wideband CQI and a Subband CQI are defined. The Wideband CQI is a CQI that is calculated with an entire band as a unit. Furthermore, the Subband CQI is a CQI that is calculated with contiguous frequency bands as a unit.
Moreover, in recent years, research and development of 5 Generation (G) systems as mobile communication systems have been actively conducted. In the 5G system, Ultra Reliable Low Latency Communications (URLLC), as a technology that is added to a normal broadband communication, are given attention. In the wireless communication system that uses the URLLC, for example, in order to cause an application that uses short-delay communication with high reliability to run, it is desirable that data transfer at a lower error rate than ever in a wireless section is realized. In this case, each of the reliability and the delay, which are obtained according to a type of service that is provided, varies, and an error rate also varies according to the type of service that is provided. As services that use the URLLC, for example, examples of dealing with malfunction of a substation and controlling the substation, controlling a power supply system that uses a smart grid technology, providing a virtual presence environment, executing an industrial control application, providing automatic operation or the tactile-sensing Internet, and so forth are considered.
It is noted that, in the related art, such as a technology for wireless communication, in the allocation of the radio resource, the terminal apparatus is notified whether non-contiguous radio resources are allocated or contiguous radio resources are allocated in a frequency domain. Furthermore, in the related art, in a case where contiguous carrier aggregation is performed, distribution of the radio resource is performed in a centralized way and in a case where non-contiguous carrier aggregation is performed, the distribution of the radio resource is performed in a distributed way.
Examples of the related art include PTL 1: Japanese Laid-open Patent Publication No. 2011-244472, PTL 2: Japanese National Publication of International Patent Application No. 2013-509120.